Anatomy of a Transverse Wave

If a snapshot of such a transverse wave could be taken so as to freeze the shape of the rope in time, then it would look like the following diagram.

• Crest are the highest points of the wave
• Troughs are the lowest points of the wave
• Amplitude is the maximum displacement of a particle from the rest position.

Some wave terminology:

1. In phase

• two particles are in phase if they have the same displacement and are moving in the same direction.
  
• particle A, B and C are in phase with each other. They have the same displacement and will move downwards in the next moment.
• particle D, E and F are also in phase. They also have the same displacement and will move upwards in the next moment.

2. Wavelength

• the shortest distance between any two points in the wave that are "in phase".
• for example the shortest distance between two successive crest
• or the shortest distance between two succesive trough

3. Period of wave, T

• time taken for the wave to produce one complete wave ( i.e. one wavelength).
• usually expressed in seconds
  
  

4. Frequency of wave

• no. of complete waves produced in one second.
• unit is measured in Hertz (Hz).
  
  
  
  
• in 1 second, one complete wave is produced for wave A. Hence its frequency is 1 Hz.
• in 1 second, 2 complete waves is produced for wave B. Hence, its frequency is 2 Hz.
• the higher the frequency, the more waves are produced in 1 second.
  
  

Mathematically, the relationship between period and frequency is:

In Summary: